I tend to go with one colour as an undercoat.
In this case a brown spray, because from brown i can easily get to skin tones, leather clothing, rusted armour and wood, red and gold and cream cloth.
So once they are under coated together and the sand applied on the bases, it's easy to get them finished very quickly.
Don't forget your handy hair dryer
I use a standard GW brush for everything, apart from some highlights.